In this article, a novel six port antenna for better spectrum utilization efficiency in cognitive radio (CR) applications is presented. In this six port antenna system, an ultra‐wideband (UWB) sensing antenna and five wideband/narrowband (NB) antennas are integrated on the same substrate in a compact area of 1134 mm². Antenna associated with port 1, which is meant for sensing, has −10 dB reflection coefficient bandwidth of 3 to 11 GHz and the antennas associated with ports 2, 3, 4, 5, and 6 have −10 dB reflection coefficient bandwidths of 3.6 to 5.8 GHz (single band), 2.9 to 3.6 GHz and 5.4 to 7.98 GHz (dual band), 7.95 to 8.38 GHz and 9 to 9.85 GHz (dual band), 8.38 to 9 GHz (single band) and 9.7 to 10.7 GHz (single band), respectively. Minimum isolation of 20 dB is attained between UWB sensing antenna and any narrowband/wideband antenna except between the antennas associated with ports 1 and 2 where minimum isolation of 12 dB is achieved over the operating bandwidth of UWB sensing antenna. Moreover, among all wideband/narrowband antennas, isolation of less than 15 dB is achieved. More importantly, the narrowband and wideband antennas meant for communication cover all frequency bands in UWB and a good match between the simulated and measured results is noticed.

中文翻译：

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紧凑的六端口天线，可在认知无线电应用中提高频谱利用率

在本文中，提出了一种新颖的六端口天线，可在认知无线电（CR）应用中提高频谱利用率。在该六端口天线系统中，在同一基板上以1134 mm ²的紧凑面积集成了一个超宽带（UWB）感应天线和五个宽带/窄带（NB）天线。。与端口1相关联的天线，用于感测，具有3至11 GHz的-10 dB反射系数带宽，与端口2、3、4、5和6相关联的天线具有3.6至10 dB的-10 dB反射系数带宽。 5.8 GHz（单频段），2.9至3.6 GHz和5.4至7.98 GHz（双频段），7.95至8.38 GHz和9至9.85 GHz（双频段），8.38至9 GHz（单频段）和9.7至10.7 GHz（单频段）乐队）。除了与端口1和端口2关联的天线之间的UWB感应天线与任何窄带/宽带天线之间的最小隔离度达到20 dB，在端口1和端口2的天线之间，在UWB感应天线的工作带宽范围内实现了12 dB的最小隔离度。此外，在所有宽带/窄带天线中，隔离度均低于15 dB。更重要的是，